Orthogonal-test-design method has been used to determine the optimal formula by phase behavior and interfacial tension studies, respectively. The effect of each component of two alkaline/surfactant/polymer flooding sy...Orthogonal-test-design method has been used to determine the optimal formula by phase behavior and interfacial tension studies, respectively. The effect of each component of two alkaline/surfactant/polymer flooding systems on interfacial tension is discussed, in which a low-price natural mixed carboxylate (SDC) is used as the major surfactant. The results indicate that the optimal composition is SDC (0.5%), alkaline NaHCO3/Na2CO3 with mass ratio of 1 (1.0%), and hydrolyzed polyacrylamide(0.1%). In the coreflood experiment, their oil recovery is increased by about 25.2% and 26.8% original oil in place, respectively.展开更多
Coreflood,interfacial tension(IFT),contact angle,and phase behavior measurements were performed to investigate the viability of a hybrid of low-salinity water,surfactant,and CO_(2) flood enhanced oil recovery(EOR)proc...Coreflood,interfacial tension(IFT),contact angle,and phase behavior measurements were performed to investigate the viability of a hybrid of low-salinity water,surfactant,and CO_(2) flood enhanced oil recovery(EOR)process.Low-permeability carbonate reservoir cores were aged for eight weeks at reservoir temperature and pressure.Coreflood and contact angle between oil droplets and core surface measurements were performed.Additional contact angle measurements on sandstone and shale cores were also performed.The coreflood sequences were seawater flood,followed by low-salinity water flood,followed by surfactant floods until residual oil saturations to each flooding sequences and finally CO_(2) injection.Coreflood in low-permeability carbonate cores show that the hybrid EOR process produces incremental oil up to twenty-five percent beyond seawater flooding.Contact angle measurements on carbonate,sandstone and shale cores indicate that wettability alteration and IFT decrease are the main oil-mobilizing mechanisms in the hybrid EOR process.The hybrid EOR process mobilizes part of the residual oil because:(i)low-salinity brine improves wettability towards hydrophilic condition favorable for surfactant flooding;(ii)surfactant in lowsalinity water solubilizes some of the remaining oil as Winsor type IImicroemulsion and lowers IFT between oil and water;and(iii)CO_(2) will follow surfactant to mobilize more of the remaining oil in the wettability-improved condition.展开更多
Surfactant-based oil recovery processes are employed to lower the interfacial tension in immiscible displacement processes,change the wettability of rock to a more water-wet system and emulsify the oil to displace it ...Surfactant-based oil recovery processes are employed to lower the interfacial tension in immiscible displacement processes,change the wettability of rock to a more water-wet system and emulsify the oil to displace it in subsurface porous media.Furthermore,these phenomena can reduce the capillary pressure and enhance spontaneous imbibition.The key factors affecting such immiscible displacement process are temperature,salinity and p H of the fluids,surfactant concentration and adsorption.Therefore,before any surfactant flooding process is applied,extensive studies of fluid-fluid and rock-fluid interactions are needed.The use of other chemicals along with surfactants in chemical enhanced oil recovery(c EOR)processes have been widely considered to exploit the synergy of individual chemicals and complement the weakness arises from each of them during immiscible displacement of fluids in porous media.Therefore,such combinations of chemicals lead to alkaline-surfactant(AS),surfactantpolymer(SP),alkaline-surfactant-polymer(ASP),and nanoparticle-surfactant(NS)flooding processes,among others.In this review study,we categorised the role and displacement mechanisms of surfactants and discussed the key factors to be considered for analysing the fluid displacement in porous media.展开更多
文摘Orthogonal-test-design method has been used to determine the optimal formula by phase behavior and interfacial tension studies, respectively. The effect of each component of two alkaline/surfactant/polymer flooding systems on interfacial tension is discussed, in which a low-price natural mixed carboxylate (SDC) is used as the major surfactant. The results indicate that the optimal composition is SDC (0.5%), alkaline NaHCO3/Na2CO3 with mass ratio of 1 (1.0%), and hydrolyzed polyacrylamide(0.1%). In the coreflood experiment, their oil recovery is increased by about 25.2% and 26.8% original oil in place, respectively.
基金The authors are grateful to Abu Dhabi National Oil Company(ADNOC)and the Petroleum Institute(PI)at Abu DhabiMarathon Center of Excellence for Reservoir Studies(MCERS)and Center for Earth Materials,Mechanics,Characterization(CEMMC)at Colorado School of Mines(CSM)for their support of this study.
文摘Coreflood,interfacial tension(IFT),contact angle,and phase behavior measurements were performed to investigate the viability of a hybrid of low-salinity water,surfactant,and CO_(2) flood enhanced oil recovery(EOR)process.Low-permeability carbonate reservoir cores were aged for eight weeks at reservoir temperature and pressure.Coreflood and contact angle between oil droplets and core surface measurements were performed.Additional contact angle measurements on sandstone and shale cores were also performed.The coreflood sequences were seawater flood,followed by low-salinity water flood,followed by surfactant floods until residual oil saturations to each flooding sequences and finally CO_(2) injection.Coreflood in low-permeability carbonate cores show that the hybrid EOR process produces incremental oil up to twenty-five percent beyond seawater flooding.Contact angle measurements on carbonate,sandstone and shale cores indicate that wettability alteration and IFT decrease are the main oil-mobilizing mechanisms in the hybrid EOR process.The hybrid EOR process mobilizes part of the residual oil because:(i)low-salinity brine improves wettability towards hydrophilic condition favorable for surfactant flooding;(ii)surfactant in lowsalinity water solubilizes some of the remaining oil as Winsor type IImicroemulsion and lowers IFT between oil and water;and(iii)CO_(2) will follow surfactant to mobilize more of the remaining oil in the wettability-improved condition.
基金the Faculty of Engineering University of Khartoum,Sudan,for the financial support of his studies at the University of Aberdeen
文摘Surfactant-based oil recovery processes are employed to lower the interfacial tension in immiscible displacement processes,change the wettability of rock to a more water-wet system and emulsify the oil to displace it in subsurface porous media.Furthermore,these phenomena can reduce the capillary pressure and enhance spontaneous imbibition.The key factors affecting such immiscible displacement process are temperature,salinity and p H of the fluids,surfactant concentration and adsorption.Therefore,before any surfactant flooding process is applied,extensive studies of fluid-fluid and rock-fluid interactions are needed.The use of other chemicals along with surfactants in chemical enhanced oil recovery(c EOR)processes have been widely considered to exploit the synergy of individual chemicals and complement the weakness arises from each of them during immiscible displacement of fluids in porous media.Therefore,such combinations of chemicals lead to alkaline-surfactant(AS),surfactantpolymer(SP),alkaline-surfactant-polymer(ASP),and nanoparticle-surfactant(NS)flooding processes,among others.In this review study,we categorised the role and displacement mechanisms of surfactants and discussed the key factors to be considered for analysing the fluid displacement in porous media.
